It would be much easier for us all to help you if we knew how many days from the first breeding and how many from the last breeding. I think I saw a post that said that your little girl was bred over a nine day period. If this is the case, she, in fact may not be due yet. Also the best indicators of an impending whelp are not the temperature but the other symptoms, like shivering or nesting behavior, refusing to eat, hiding, etc. I know it is really hard to wait and like I said you start to feel a little wonky after a while, but it is in the best interest of your little girl to just sit it out and wait if she seems happy and healthy. Talk to your vet, if you like but I am sure he or she will just tell you to sit tight.